The invention concerns a rearview mirror for vehicles, in particular, for commercial vehicles wherein said mirror possesses an optical imaging apparatus in accord with the generic concept of claim 1.
US-PS-4,882-565 has disclosed a rearview mirror for vehicles, wherein in the reflecting surface an indicator device is integrated, which is provided with light from an illumination means located behind the mirror surface. With this device, simple warning signals or stylized presentations of various functional units can be presented and brought to the rearview mirror for attention. The images produced by a camera are not presented here.
Upon making a turn with a vehicle from a subordinate street into a main thoroughfare, normally, the driver makes use of the rear vision mirror, before he turns. In the case of a right turn, in doing this, he has not only the right side mirror with the visible rearward area, but also the view to the right-front over the mirror in his field of sight. To be aware of risks or traffic on the left side, he must turn his head and if necessary, use the left rearview mirror. In heavy traffic, therefore, he is obliged to change both his direction of vision and the position of his head, wherein respectively, while he is looking to one side, the other side is not being tended to. This can lead to dangerous situations.
It is the purpose of the present invention, to develop a rearview mirror with an optical imaging device, of such a nature, that the most different areas surrounding the vehicle will come to the attention of the driver.
The achievement of this purpose is accomplished by the features of claim 1.
By means of the provision of a monitor, which is placed in the rearview mirror, an image produced by a camera can be transmitted to the said monitor. The camera can be directed to a field of vision, which is not in the view angle of the driver when he looks into the mirror. With the advantage of the invention, the driver, with one glance, can not only discern the area directly in the reflected angle of the mirror, as well as the area in front of the mirror, but he can also see another area on the monitor in the mirror without needing to change his direction of view nor to turn his head. In the case of the monitor, advantageously an LCD image is employed and the camera would, advantageously, also be a CCD-camera.
In accord with an advantageous embodiment of the invention, the monitor is placed in the edge area of the mirror, that is, the mirror pane, in order not to interfere with the fundamental purpose of the mirror. This opens up the possibility, that the monitor need not be integrated into the mirror pane, but rather be placed in a position under, beside or above the mirror pane. The placement of the monitor would be effected by an appropriate recess in the mirror housing.
In accord with an advantageous embodiment of the invention, following Claim 3, the camera is likewise installed within the mirror housing, whereby the incident light on the camera is made possible by a corresponding opening in the mirror housing.
In accord with an advantageous embodiment of the invention, enabled by Claim 4, the camera is designed to be pivoted, so that different areas about the vehicle can be brought into view and depicted in the monitor. When backing up is a necessity, then the zone behind the vehicle can be seen in the monitor.
In accord with another advantageous embodiment of the invention, claim 7 allows for a plurality of cameras. With this multi-camera arrangement, switching among the individual cameras again allows various areas around the vehicle to be presented in the monitor.
If this latter plan is followed, then the pivoting of the camera becomes redundant. The respective camera can be placed in an optimal position to scan the current area to be overseen. The camera for the backing up operation is logically to be installed on the back side of the vehicle.
If, additionally, a plurality of monitors are available (see Claim 8) then, under certain circumstances, selective switching from camera to camera becomes unnecessary, since one camera each can be apportioned to one monitor. Additionally, the possibility also exists that on various monitors and particularly in different areas of presentation, in one monitor additional data can be shown, such as temperature, speed, assured clear distance behind, to the front, or to the side can be imaged in. The different presentation areas of a monitor should be understood in the sense, that on the monitor different items can be shown by means of an image within an image format.
In accord with a further advantageous embodiment, as presented in Claim 9, the rearview mirror can encompass a first and a second monitor. The first monitor is connected with a camera in one rearview mirror, and the second monitor is connected to a camera in the other side rearview mirror of a vehicle. Thus, this arrangement allows a greater area around the vehicle to be scanned at one glance.
By means of an image and data memory apparatus, as taught by Claims 11 and 12, what is essentially a xe2x80x9cblack-boxxe2x80x9d function can be brought about. For this purpose, the continuous images of the last five minutes, from one or more cameras can be retained in memory. Additionally, relevant data such as temperature, weather, time, and speed can also be saved. By this means, an accident can be more easily reconstructed.
In accord with Claim 12, the image surface of the monitor(s) is angled differently than that of the mirror surface. This is to prevent showing the same image in the monitor as is normally reflected in the mirror.
By means of a digital zoom, that is, by the digital selection of an image component, as stated in Claim 13, a function can be realized similar to that obtained by the pivoting of a camera.